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Hooker Headers 12646

Hooker Headers LS Engine and Transmission Mount for 1973-87 GM 2WD Pickup

Hooker Headers 12646

520-12646

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Hooker Headers 12646 Hooker Headers LS Engine and Transmission Mount for 1973-87 GM 2WD Pickup $230.95
Transmission Crossmember for LS Engine Swap
  • GM 4L60, 4L65, 4L70, 4L75, 4L80, 4L85, TH350, TH400, 200-4R, 700R4 Automatic Transmission
  • LS T56, T56 Magnum Manual Transmission and TH350, 700R4 Automatic Transmission Require Adapter Bracket 520-12645

  • Hooker Headers 12646 Details

    Crossmembers

    1973-87 GM C-10/20 2WD LS swap 4L60/4L80/TH350/TH400/2004R/ T56/T56 Magnum Transmission Crossmember. 12645HKR adapter bracket is also required for installation of a TH350, 700R4, T56 or T56 Magnum transmission. Integral component of the complete Hooker swap system for this application. Component features unique geometry that is not compatible for use with any other brand of engine mounting components. 12645HKR adapter bracket is also required for installation of a TH350, 700R4, T56 or T56 Magnum transmission.

  • Facilitates installation of a 4L60/4L80/TH350/TH400/2004R/T56/T56 behind an LS engine in 1973-87 GM C-10/20 2WD applications (may require add-on bracket, see installation notes)
  • Designed using CAD modeling/FEA analysis for optimal fitment, strength, weight, safety and appearance
  • Welded steel construction
  • Provides an optimum engine/transmission inclination angle that is critical to obtaining suitable U-joint working angles, when installed with Hooker p/n 520-12621 engine mounts
  • Designed in conjunction with other Hooker GM C-10/20 engine swap brackets to provide bolt-in installation of Hooker LS swap manifolds, headers and exhaust systems for this application
  • Provides the highest clearance available for up to 3-inch exhaust system routing

  • Specifications:

    Manufacturer's Part Number:
    12646

    Engineered specifically for C10/20 Pickup LS Engine Swaps

    These mounting brackets are part of the most comprehensively engineered system of mounting components, headers and exhaust systems available for this application.
    The entire Hooker swap system is designed to decrease your total swap installation effort and cost, while increasing the engineered quality of your vehicle and compatibility of these components with other popular aftermarket components. For best fitment and overall component clearances, Hooker headers and mounting components for this swap application are designed with a chassis-centered engine and transmission location, which varies only slightly from the original minor passenger's side offset used by GM. The engine and transmission have also been positioned to enable hassle-free installation and to promote good vehicle handling performance. The unique design geometry of these engine brackets require the use of Hooker transmission crossmembers and headers to achieved the designed fitment between all components in this swap application.
    Use of any non-Hooker brand transmission crossmember or headers will have adverse effects on the ease of installation, component clearance, ground clearance and engine inclination angle (3° with Hooker engine mounts and transmission crossmembers) you can expect from your installation. With these components installed, your driveline will be purposely configured with compound U-joint angles, due to the chassis-centered alignment of your engine/transmission and the stock pinion offset of your rear differential.
    These brackets are designed to be used in conjunction with stock OE clamshell style engine mounts that will be retrofitted into the swap vehicle through the use of the specially designed spacer plates included with this kit. The OE clamshell mounts and the long horizontally installed bolts used to secure them to the Hooker brackets are not included with this kit and will need to be purchased separately. In order to achieve the intended fitment and clearances of these components, it is highly recommended that new clamshell mounts (Anchor brand p/n 2292 or equivalent) be installed at the time of installation.
    The combined use of these mounting brackets and related Hooker transmission swap crossmembers, will allow installation of an LS engine with a GM TH350, TH400, 700R4, 2004R, 4L60, 4L65, 4L70, 4L75, 4L80 or 4L85 automatic trans or a T56/T56 Magnum manual trans into any 1973-87 GM C10/20 pickup.
    These engine swap mounting brackets were specifically designed for bolt-in compatibility with Hooker transmission swap crossmembers, headers and exhaust systems, and Holley LS oil pans (p/n 510-302-1 or 510-302-2) and accessory drive components for this application.

    Important Application and Installation Note
    These LS swap engine mount brackets were specifically designed for compatibility with:
  • Hooker Headers for LS Engine Swap 1973-87 GM 2WD Pickup
  • Hooker Headers exhaust systems (p/n 520-42537, 520-42538, 520-42539 or 520-42540)
  • Holley GM LS Engine Retrofit Oil Pan (p/n 510-302-1)
  • Holley GM LS Engine Retrofit Oil Pan 1967-69 Camaro/1968-74 Nova, Extra clearance for crossmember at the front of the pan (p/n 510-302-2, cannot be used with LS7 engines or ''stroker'' engines greater than 3.62'' stroke.)
    and accessory drive components for this application. Using ANY components other than what is listed here will result in misalignment and interference issues with these Hooker and Holley components.

    Features
  • Include engine mounting brackets and hardware only. These components must be installed with a compatible Hooker transmission crossmember to obtain proper installed drivetrain alignment.
  • Installed using the improved design 1972-up GM clamshell engine mounts.
  • Fully compatible with Holley LS swap oil pans and accessory drive brackets.
  • Hooker C10/C20 engine brackets work with the Holley p/n 510-302-1 or 510-302-2 oil pans to provide optimized component clearances and U-joint working angles when used in conjunction with Hooker LS engine swap transmission crossmembers for the same application. This design metric is poorly addressed in 'other' existing LS swap mounting components.
  • Engine placement provides comprehensive compatibility with multiple accessory drive set-ups and transmissions.

    JEGS Easy Kits are designed by JEGS high performance racing professionals to help you get all the performance parts you need for your race car, hot rod or truck.

  • Does Hooker Headers 12646 fit your vehicle?

    Narrow Results

    1981 CHEVROLET C10 PICKUP

    • CC: 5031
    • Liter: 5.0
    • SubModel: SILVERADO
    • CUI: 305
    • EngineType: V8 ( 5.0 L / 305 )

    1979-1980 GMC C1500 PICKUP

    • EngineType: ALL
    • SubModel: HEAVY HALF

    1983-1984 CHEVROLET C10 PICKUP

    • EngineType: ALL
    • SubModel: ALL

    1977 CHEVROLET C10 PICKUP

    • EngineType: ALL
    • SubModel: BASE

    1985-1986 CHEVROLET C20 PICKUP

    • EngineType: ALL
    • SubModel: SILVERADO

    1981 CHEVROLET C10 PICKUP

    • CC: 4097
    • Liter: 4.1
    • SubModel: DELUXE
    • CUI: 250
    • EngineType: L6 ( 4.1 L / 250 )

    1975-1980 CHEVROLET C10 PICKUP

    • EngineType: ALL
    • SubModel: SCOTTSDALE

    1975-1980 CHEVROLET C10 PICKUP

    • EngineType: ALL
    • SubModel: SILVERADO

    1981 CHEVROLET C10 PICKUP

    • CC: 5031
    • Liter: 5.0
    • SubModel: CHEYENNE
    • CUI: 305
    • EngineType: V8 ( 5.0 L / 305 )

    1976 GMC C1500 PICKUP

    • Liter: 7.4
    • SubModel: BASE
    • CUI: 454
    • EngineType: V8 ( 7.4 L / 454 )

    1979-1981 GMC C1500 PICKUP

    • EngineType: ALL
    • SubModel: STREET COUPE

    1985 GMC C1500 PICKUP

    • Liter: 6.2
    • Aspiration: N
    • SubModel: BASE
    • Engine Vin: C
    • CUI: 379
    • EngineType: V8 ( 6.2 L / 379 )

    1976 GMC C1500 PICKUP

    • Liter: 4.1
    • SubModel: BASE
    • CUI: 250
    • EngineType: L6 ( 4.1 L / 250 )

    1980 CHEVROLET C10 PICKUP

    • CC: 4097
    • Liter: 4.1
    • SubModel: BIG TEN
    • CUI: 250
    • EngineType: L6 ( 4.1 L / 250 )

    1976 GMC C1500 PICKUP

    • Liter: 5.7
    • SubModel: BASE
    • CUI: 350
    • EngineType: V8 ( 5.7 L / 350 )

    1973 CHEVROLET C20 PICKUP

    • CC: 5736
    • Liter: 5.7
    • SubModel: BASE
    • CUI: 350
    • EngineType: V8 ( 5.7 L / 350 )

    1981 GMC C1500 PICKUP

    • Liter: 5.0
    • SubModel: BASE
    • CUI: 305
    • EngineType: V8 ( 5.0 L / 305 )

    1979-1980 GMC C1500 PICKUP

    • Liter: 4.8
    • SubModel: BASE
    • CUI: 292
    • EngineType: L6 ( 4.8 L / 292 )

    1974 CHEVROLET C20 PICKUP

    • CC: 5737
    • Liter: 5.7
    • SubModel: BASE
    • CUI: 350
    • EngineType: V8 ( 5.7 L / 350 )

    1976 GMC C1500 PICKUP

    • EngineType: ALL
    • SubModel: SIERRA CLASSIC

    1980 CHEVROLET C10 PICKUP

    • Liter: 4.8
    • SubModel: BIG TEN
    • CUI: 292
    • EngineType: L6 ( 4.8 L / 292 )

    1979-1981 GMC C1500 PICKUP

    • EngineType: ALL
    • SubModel: HIGH SIERRA

    1979-1981 CHEVROLET C20 PICKUP

    • EngineType: ALL
    • SubModel: CHEYENNE

    1974 CHEVROLET C10 PICKUP

    • CC: 5737
    • Liter: 5.7
    • SubModel: BASE
    • CUI: 350
    • EngineType: V8 ( 5.7 L / 350 )

    1985 GMC C1500 PICKUP

    • Liter: 5.0
    • SubModel: BASE
    • CUI: 305
    • EngineType: V8 ( 5.0 L / 305 )

    1973 CHEVROLET C20 PICKUP

    • CC: 5736
    • Liter: 5.7
    • SubModel: BASE
    • CUI: 350
    • EngineType: V8 ( 5.7 L / 350 )

    1982 CHEVROLET C20 PICKUP

    • Liter: 4.8
    • SubModel: BASE
    • CUI: 292
    • EngineType: L6 ( 4.8 L / 292 )

    1975-1980 CHEVROLET C10 PICKUP

    • EngineType: ALL
    • SubModel: CHEYENNE

    1985 GMC C1500 PICKUP

    • EngineType: ALL
    • SubModel: SIERRA CLASSIC

    1981 CHEVROLET C10 PICKUP

    • CC: 4097
    • Liter: 4.1
    • SubModel: CHEYENNE
    • CUI: 250
    • EngineType: L6 ( 4.1 L / 250 )

    1975-1978 CHEVROLET C20 PICKUP

    • EngineType: ALL
    • SubModel: ALL

    1974 CHEVROLET C10 PICKUP

    • CC: 4801
    • Liter: 4.8
    • SubModel: BASE
    • CUI: 292
    • EngineType: L6 ( 4.8 L / 292 )

    1988 CHEVROLET R20 PICKUP

    • CC: 5031
    • Liter: 5.0
    • SubModel: CUSTOM DELUXE
    • CUI: 305
    • EngineType: V8 ( 5.0 L / 305 )

    1985 CHEVROLET C10 PICKUP

    • EngineType: ALL
    • SubModel: CUSTOM

    1987 CHEVROLET R20 PICKUP

    • EngineType: ALL
    • SubModel: ALL

    1981 CHEVROLET C10 PICKUP

    • CC: 5735
    • Liter: 5.7
    • SubModel: CUSTOM
    • CUI: 350
    • EngineType: V8 ( 5.7 L / 350 )

    1974 CHEVROLET C20 PICKUP

    • CC: 4801
    • Liter: 4.8
    • SubModel: BASE
    • CUI: 292
    • EngineType: L6 ( 4.8 L / 292 )

    1979-1980 GMC C1500 PICKUP

    • Liter: 5.0
    • SubModel: BASE
    • CUI: 305
    • EngineType: V8 ( 5.0 L / 305 )

    1981 CHEVROLET C10 PICKUP

    • CC: 5031
    • Liter: 5.0
    • SubModel: CUSTOM
    • CUI: 305
    • EngineType: V8 ( 5.0 L / 305 )

    1979-1981 GMC C1500 PICKUP

    • Liter: 4.1
    • SubModel: BASE
    • CUI: 250
    • EngineType: L6 ( 4.1 L / 250 )

    1987 CHEVROLET R10 PICKUP

    • EngineType: ALL
    • SubModel: ALL

    1974 CHEVROLET C10 PICKUP

    • CC: 7441
    • Liter: 7.4
    • SubModel: BASE
    • CUI: 454
    • EngineType: V8 ( 7.4 L / 454 )

    1973-1974 CHEVROLET C20 PICKUP

    • CC: 4098
    • Liter: 4.1
    • SubModel: BASE
    • CUI: 250
    • EngineType: L6 ( 4.1 L / 250 )

    1981 CHEVROLET C10 PICKUP

    • CC: 4097
    • Liter: 4.1
    • SubModel: SILVERADO
    • CUI: 250
    • EngineType: L6 ( 4.1 L / 250 )

    1979-1982 CHEVROLET C20 PICKUP

    • EngineType: ALL
    • SubModel: SILVERADO

    1973-1974 CHEVROLET C20 PICKUP

    • CC: 7441
    • Liter: 7.4
    • SubModel: BASE
    • CUI: 454
    • EngineType: V8 ( 7.4 L / 454 )

    1987 GMC R1500 PICKUP

    • EngineType: ALL
    • SubModel: ALL

    1974 GMC C1500 PICKUP

    • CC: 5737
    • Liter: 5.7
    • SubModel: BASE
    • CUI: 350
    • EngineType: V8 ( 5.7 L / 350 )

    1980 CHEVROLET C10 PICKUP

    • Liter: 6.6
    • SubModel: BIG TEN
    • CUI: 400
    • EngineType: V8 ( 6.6 L / 400 )

    1982 CHEVROLET C10 PICKUP

    • EngineType: ALL
    • SubModel: CUSTOM

    1979-1980 GMC C1500 PICKUP

    • Liter: 7.4
    • SubModel: BASE
    • CUI: 454
    • EngineType: V8 ( 7.4 L / 454 )

    1974 CHEVROLET C10 PICKUP

    • CC: 4098
    • Liter: 4.1
    • SubModel: BASE
    • CUI: 250
    • EngineType: L6 ( 4.1 L / 250 )

    1974 GMC C1500 PICKUP

    • CC: 7441
    • Liter: 7.4
    • SubModel: BASE
    • CUI: 454
    • EngineType: V8 ( 7.4 L / 454 )

    1981 CHEVROLET C10 PICKUP

    • Liter: 5.0
    • SubModel: SCOTTSDALE
    • CUI: 305
    • EngineType: V8 ( 5.0 L / 305 )

    1982-1984 GMC C1500 PICKUP

    • EngineType: ALL
    • SubModel: ALL

    1974 GMC C1500 PICKUP

    • CC: 4801
    • Liter: 4.8
    • SubModel: BASE
    • CUI: 292
    • EngineType: L6 ( 4.8 L / 292 )

    1973 CHEVROLET C20 PICKUP

    • CC: 5031
    • Liter: 5.0
    • SubModel: BASE
    • CUI: 307
    • EngineType: V8 ( 5.0 L / 307 )

    1975 GMC C1500 PICKUP

    • EngineType: ALL
    • SubModel: ALL

    1985 CHEVROLET C10 PICKUP

    • EngineType: ALL
    • SubModel: SCOTTSDALE

    1974 GMC C1500 PICKUP

    • CC: 4098
    • Liter: 4.1
    • SubModel: BASE
    • CUI: 250
    • EngineType: L6 ( 4.1 L / 250 )

    1979-1980 CHEVROLET C20 PICKUP

    • EngineType: ALL
    • SubModel: CUSTOM DELUXE

    1982 CHEVROLET C10 PICKUP

    • EngineType: ALL
    • SubModel: SILVERADO

    1979-1981 GMC C1500 PICKUP

    • Liter: 5.7
    • SubModel: BASE
    • CUI: 350
    • EngineType: V8 ( 5.7 L / 350 )

    1976 GMC C1500 PICKUP

    • Liter: 6.6
    • SubModel: BASE
    • CUI: 400
    • EngineType: V8 ( 6.6 L / 400 )

    1976 GMC C1500 PICKUP

    • EngineType: ALL
    • SubModel: SIERRA GRANDE

    1979-1982 CHEVROLET C20 PICKUP

    • EngineType: ALL
    • SubModel: SCOTTSDALE

    1981 CHEVROLET C10 PICKUP

    • CC: 4097
    • Liter: 4.1
    • SubModel: CUSTOM
    • CUI: 250
    • EngineType: L6 ( 4.1 L / 250 )

    1980 CHEVROLET C10 PICKUP

    • Liter: 7.4
    • SubModel: BIG TEN
    • CUI: 454
    • EngineType: V8 ( 7.4 L / 454 )

    1980 CHEVROLET C10 PICKUP

    • Liter: 5.0
    • SubModel: BIG TEN
    • CUI: 305
    • EngineType: V8 ( 5.0 L / 305 )

    1988 CHEVROLET R20 PICKUP

    • Liter: 4.3
    • SubModel: CUSTOM DELUXE
    • CUI: 262
    • EngineType: V6 ( 4.3 L / 262 )

    1981 CHEVROLET C10 PICKUP

    • Liter: 5.7
    • SubModel: SILVERADO
    • CUI: 350
    • EngineType: V8 ( 5.7 L / 350 )

    1985-1986 CHEVROLET C20 PICKUP

    • EngineType: ALL
    • SubModel: CUSTOM

    1981 CHEVROLET C20 PICKUP

    • EngineType: ALL
    • SubModel: DELUXE

    1974 CHEVROLET C10 PICKUP

    • CC: 4801
    • Liter: 4.8
    • SubModel: BASE
    • CUI: 292
    • EngineType: L6 ( 4.8 L / 292 )

    1978-1979 CHEVROLET C10 PICKUP

    • EngineType: ALL
    • SubModel: BIG TEN

    1979-1980 GMC C1500 PICKUP

    • Liter: 6.6
    • SubModel: BASE
    • CUI: 400
    • EngineType: V8 ( 6.6 L / 400 )

    1979-1981 GMC C1500 PICKUP

    • EngineType: ALL
    • SubModel: SIERRA CLASSIC

    1981 CHEVROLET C10 PICKUP

    • Liter: 5.7
    • SubModel: SCOTTSDALE
    • CUI: 350
    • EngineType: V8 ( 5.7 L / 350 )

    1983-1984 CHEVROLET C20 PICKUP

    • EngineType: ALL
    • SubModel: ALL

    1981 CHEVROLET C10 PICKUP

    • Liter: 5.7
    • SubModel: DELUXE
    • CUI: 350
    • EngineType: V8 ( 5.7 L / 350 )

    1977-1978 GMC C1500 PICKUP

    • EngineType: ALL
    • SubModel: ALL

    1980 CHEVROLET C10 PICKUP

    • Liter: 5.7
    • SubModel: BIG TEN
    • CUI: 350
    • EngineType: V8 ( 5.7 L / 350 )

    1981 CHEVROLET C10 PICKUP

    • CC: 4097
    • Liter: 4.1
    • SubModel: SCOTTSDALE
    • CUI: 250
    • EngineType: L6 ( 4.1 L / 250 )

    1976 GMC C1500 PICKUP

    • Liter: 4.8
    • SubModel: BASE
    • CUI: 292
    • EngineType: L6 ( 4.8 L / 292 )

    1985 GMC C1500 PICKUP

    • EngineType: ALL
    • SubModel: HIGH SIERRA

    1986 CHEVROLET C10 PICKUP

    • EngineType: ALL
    • SubModel: ALL

    1981-1982 CHEVROLET C20 PICKUP

    • EngineType: ALL
    • SubModel: CUSTOM

    1985 GMC C1500 PICKUP

    • Liter: 4.3
    • SubModel: BASE
    • CUI: 262
    • EngineType: V6 ( 4.3 L / 262 )

    1975-1980 CHEVROLET C10 PICKUP

    • EngineType: ALL
    • SubModel: CUSTOM DELUXE

    1976 GMC C1500 PICKUP

    • EngineType: ALL
    • SubModel: HIGH SIERRA

    1982 CHEVROLET C10 PICKUP

    • EngineType: ALL
    • SubModel: SCOTTSDALE

    1985 GMC C1500 PICKUP

    • Liter: 5.7
    • SubModel: BASE
    • CUI: 350
    • EngineType: V8 ( 5.7 L / 350 )

    1974 GMC C1500 PICKUP

    • CC: 5737
    • Liter: 5.7
    • SubModel: BASE
    • CUI: 350
    • EngineType: V8 ( 5.7 L / 350 )

    1973 CHEVROLET C20 PICKUP

    • CC: 4801
    • Liter: 4.8
    • SubModel: BASE
    • CUI: 292
    • EngineType: L6 ( 4.8 L / 292 )

    1974 CHEVROLET C20 PICKUP

    • CC: 4801
    • Liter: 4.8
    • SubModel: BASE
    • CUI: 292
    • EngineType: L6 ( 4.8 L / 292 )

    1985 CHEVROLET C10 PICKUP

    • EngineType: ALL
    • SubModel: SILVERADO

    1973 GMC C1500 PICKUP

    • EngineType: ALL
    • SubModel: ALL

    1979-1981 GMC C1500 PICKUP

    • EngineType: ALL
    • SubModel: SIERRA GRANDE

    1985-1986 CHEVROLET C20 PICKUP

    • EngineType: ALL
    • SubModel: SCOTTSDALE

    1981 CHEVROLET C10 PICKUP

    • CC: 5031
    • Liter: 5.0
    • SubModel: DELUXE
    • CUI: 305
    • EngineType: V8 ( 5.0 L / 305 )
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